Subject: RAIDframe for dom0?
To: None <port-xen@netbsd.org>
From: Greg Troxel <gdt@ir.bbn.com>
List: port-xen
Date: 08/10/2005 10:41:40
I would like to set up a machine with NetBSD/Xen and RAID-1 (on 2
identical disks).  Ideally, I'd like to be able to boot off a RAID-1
root, with xen and netbsd-XEN0 both on that filesystem, with boot
blocks on the other disk that can boot off the second disk.

To be a bit more concrete, I envision an 8G /dev/raid0 with wd0a and
wd0b, on which I put / swap /var /usr as raid0[abef], and a large
(200G perhaps - whatever's left of a large disk) /dev/raid1 of wd0e
and wd1e, with raid1e mounted on /n0.  I'll put domU disk files in
/n0.

I know i386 boot can boot from RAID-1, but with Xen you have to use grub,
and it seems grub doesn't grok RAID-1:

  http://mail-index.netbsd.org/port-xen/2005/05/02/0001.html

So, with a small partition for /grub, can grub's ffs_stage1_5 (?) and
stage2 read from RAID-1?
Can I have a /grub0 and /grub1 on each disk, and install grub on both
disks and get the 'system can boot if either disk is working' feature
I'd like?

Any hints on how to install such a system would be appreciated,
although i suppose aside from making a partition for grub it's a plain
i386 question before one installs grub and boots xen+XEN0 rather than
GENERIC.

    Thanks,
    Greg